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Non-Corrosion Properties of Stainless Steels
Stainless Steels: it is not only the corrosion resistance that mattersStainless steels are often rightly associated
with corrosion resistance ...
but they can do much more!
The following examples illustrate
the usefulness of other properties
of stainless steel long products.
Non-Corrosion Properties of Stainless Steels
Background on stainless steel long products processing routes and productsStainless steel long products cover all stainless steels obtained
from the hot rolling of semis, bars and wire.
Semis, also called billets, have a square cross-section with round
edges, and are almost entirely used for either hot forging (valve
bodies for instance) or hot re-rolling by independent re-rollers.
Bars above 20 mm are usually produced directly by hot rolling.
They are then heat treated, descaled, straightened and usually
machined/ground to achieve the required tolerance (H9 to K13
usually) and surface finish.
Bars having a diameter between 20 mm down to 5 mm are
usually obtained by straightening of hot rolled, annealed and
pickled wire rod (see below). Drawing benches allow direct
conversion of wire rod to bright drawn bars, tolerance H9.
Tolerances H8 or lower require a further grinding operation. Bars
below 5 mm require a further cold-drawing operation (see below)
before bar conversion. Most of the bars are machined into a
very wide variety of parts, some of them very complex with tight
tolerances.
Hot rolled wire rod in irregular wound coils is heat treated,
then pickled in acid baths to remove the black oxide layer. Hot
rolled wire rod diameter ranges from 5 to 32 mm approximately.
Broadly speaking there are three main applications for wire rod:
Cold or warm heading for the production of fasteners or cutlery
(for the latter, some of the stainless grades require hot forging).
In a typical fastener production, say a bolt with an hexagonal
head, the cold leading machine performs successive operations
of calibration, cutting, cold heading in 2 to 3 blows, cutting the
hexagonal shape, delivering thus a fastener which needs only the
final thread-rolling to be finished.
Bar conversion (see above)
Drawn wire, obtained by drawing coil-to-coil on single or multi-
pass machines (up to 14 passes) followed by annealing as
required, results in a wire of the desired diameter and mechanical
properties. For fine wire (roughtly below 0.8 mm) more multi-
pass drawing and annealing cycles are necessary to achieve the
required wire properties. Ultra-fine wire, down to about 0.015 mm
can thus be obtained (using appropriate re-melted stainless steel
grades). The main areas of use of drawn wire are: � Forming wire: bent and formed parts for household, building
and miscellaneous applications � Spring wire: used for the manufacture of high performance
springs � Welding wire: used for MIG, TIG or electrode welding of steels
(mostly stainless) � Fine wire: used for mesh (decorative and filtration
applications) or braids (for flexible hoses) � Profiled wire: used for oil, water, coil, food and beverage
filtration, as well as for decorative purposes � Wire for machining: either converted to bars down to about
2 mm on small drawing benches (see bars above) or for machining from coils on the “Escomatic” machines. Such a wide variety of applications and processing routes call for over 200 stainless grades, a complexity inherent to long products.
Non-Corrosion Properties of Stainless SteelsPhysical Properties
Electrical appliancesDirect acting Solenoid Valve
In this type of valve, the valve shaft is put into motion when
current flows through the surrounding coil. The stainless steel
which is used must be “soft” magnetic (i.e. must possess a
low coercitive field Hc). This generally requires special heat
treatments to be carried out. Solenoids of this type are used
extensively to control electrical appliances.
Grade: EN 1.4105 +Si or AISI 430FR, EN 1.4106
Proprietary grades
Why Stainless Steel?
Soft magnetic
Non-Corrosion Properties of Stainless SteelsPhysical Properties
MedicalMagnetic Resonance Imaging
Magnetic Resonance Imaging (MRI) is a powerful medical imaging
technique. MRI is based on the physical and chemical principles
of nuclear magnetic resonance (NMR), a technique used to gain
information about the nature of molecules.
Grades: Austenitic stainless steels
Why Stainless Steel?
Non magnetic
During a MRI scan, a strong magnetic field aligns the nuclear
magnetisation of (usually) hydrogen atoms in water in the body.
The use of non-magnetic materials in the equipment is therefore
mandatory. A computer interprets the data, and creates images
that display the different resonance characteristics of different
tissue types. Trained medical staff can examine the resulting
image and use the information to diagnose many different types
of medical conditions within the human body.
Non-Corrosion Properties of Stainless SteelsPhysical Properties
Oil and gasNon Magnetic Drill CollarsDrill collars are heavy walled tubes, up to 300 mm in diameter
and having a length of about 10 m. They provide weight on
the drill bit and house sensitive electronic equipment. These
collars are non magnetic so that they do not interfere with the
electronic devices used to monitor the position of the drill bit
(such as Measurement While Drilling equipment). This electronic
equipment uses the earth’s magnetic field as a positioning
guide and any magnetic steels in the vicinity of this measuring
equipment would obscure the reading.
NMDC
Why Stainless Steel? � Non magnetic � Good mechanical properties
Grades: 16Cr 20Mn 2Mo 0,4N proprietary analyses
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Non magnetic � Good mechanical properties
Physical Properties
EnergyGenerator End Rings
The diameter of the end ring of a turbo generator can be
between 0.5 and 1.6 meters. The end ring must pass stringent
tests to ensure it can operate without deformation at speeds
ranging from 3,000 to 3,600 revolutions per minute. A 20 %
overspeed test is also conducted before the end-rings are
passed for use.
Non-magnetic stainless steel reduced the losses in the ring
that are caused by eddy currents and thermal stresses. The
steel also possesses a high yield strength in order to avoid
plastic deformation due to the high stresses produced by the
shrink-fit and centrifugal forces.
Grade: DIN: 1.3816
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Non magnetic � Abrasion resistance
Grades: EN1.430, AISI: 304, AISI: 202 modified
Physical Properties
EnergyCoal Filtration BasketsThe run-of-mine from a coal mine requires the separation of coal (density about 1.4)
from the stones (density about 2.2), which is usually done by gravity in “heavy media” (a
slurry of water and magnetite, adjusted to a density of about 1.6).
The coal is then de-watered, (i.e. separated from the remaining water and magnetite),
usually in centrifuges (vertical or horizontal) that use rotating slotted baskets. These
baskets are made of amagnetic stainless steel to avoid “sticking” of magnetite on the
surface.
Basket
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Coefficient of Expansion similar to that of glass � Electrical conductivity
Grades: EN1.4762, AISI 446
Physical Properties
Coefficient of Thermal ExpansionGlass-to Metal seals
They provide a way to hermetically pass an electrical conductor
from one environment to another. The glass, as well as providing
the seal, acts as an insulator between the pins and the housing.
These conductor feeds can thus be used for many applications
such as: vacuum components, sensor or transducer housings, in
harsh environments and in medical implantable devices.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Electrical conductivity � Oxidation resistance
Grades: Fe - Cr - Al stainless steels
Physical Properties
Domestic AppliancesHeating elementsFerritic-chromium-aluminium stainless steels combine a
controlled electrical resistivity with outstanding oxidation
resistance. The oxidation resistance is a result of the high
chromium and aluminium content in the stainless.
The heating elements are used in many domestic applications
such as toasters and hair dryers.
They also have industrial uses in fan heaters and industrial
furnaces.
For more demanding applications, and particularly at higher
temperatures, nickel-chromium alloys or ceramics are used (for
example, SiC, MoSi2).
Fabrication process: Hot rolled wire rod is drawn and annealed in
successive steps into small diameter wire. This is then wound to
form heating elements for electrical appliances.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Good mechanical properties at cryonic temperatures � Dimensional stability during thermal cycling
Grades:
Body and disk: EN1.4307 (ASTM: A351 CF3M)
Stem: EN1.4401 (ASTM: A182 F316)
Low-Temperature Properties
Oil and gasCryonic valveThis valve operates at cryonic
temperatures, in harsh weather
conditions.
Dimensional stability is required during
cycles ranging from ambient temperature
to liquid natural gas temperatures
(usually -196° C) to avoid leakage.
Perfect reliability is essential.
107 cm (42 inch) valve Tapped valve after testing in liquid nitrogen
Valve at the LNG terminal in Bilbao, Spain
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Mechanical properties at cryonic temperatures � Cleanability
Grades: Austenitic stainless steels
Low-Temperature Properties
BiologyFittings and valves for cryonic equipmentStainless steel fittings, valves and ancillary equipment are
routinely used in biology for cryonic storage of liquid gas in
Dewar vessels.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Mechanical properties at low temperatures � Perfect for contact with food and beverages
Grades: EN1.4016, AISI 430
Low-Temperature Properties
White goodsIce augerRefrigerators with crushed ice dispensers are equipped with a
cooling/heating unit which produces ice shells and then released
them into a tray. They are then crushed by an helical-shaped ice
auger to supply the ice for water and other drinks.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Good mechanical properties at elevated temperatures
Grades: Proprietary 0.2C 13Cr Nb V super martensitic stainless steels
High-Temperature Properties
EnergySteam Turbine BladesCoal, gas and nuclear power plants produce
electricity by heating water to create steam.
The steam is driven through turbine blades
at very high pressure. The blades drive the
turbine which generates electricity.
The typical operating temperature of the
steam is around 600° C. The blades must be
tough and resistant to creep, stress, corrosion
and cracking.
The super-martensitic stainless steels used
in these blades are perfect for use in this
application.
Fabrication process: Large blades are forged
from billets, machined, then heat-treated.
Small blades are heat-treated and machined
from flat bars.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Good mechanical properties at elevated temperatures
Grades:Exhaust: Austenitic grades such as EN1.4882 and 1.4871
Intake and shaft: Martensitic grades such as EN1.4718
High-Temperature Properties
Automotive:Intake and Exhaust ValvesExhaust valves in combustion engines operate at high
temperatures. However, the gas temperature of intake valves is
much lower.
This dictates the use of different stainless grades for the
intake and exhaust valves. Stainless steel provides optimum
performance at the lowest cost.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Good mechanical properties at elevated temperatures
Grades: EN1.4845; AISI 310
EN1.4841; AISI 314
EN1.4886; AISI 330
High-Temperature Properties
Furnace EquipmentConveyor beltsWidely used for continuous baking or cooking of food.
Very frequently used also in all industries wherever baking,
firing, annealing, etc. is needed.
The stainless belt undergoes repeated thermal cycling.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Does not become brittle after long exposure to hydrogen � Durability
Grades: EN1.4435; AISI 316L
Strength and Toughness
AutomotiveHigh Pressure Hydrogen Equalizer Component
Hydrogen powered cars will require high
pressure (+700 bar) hydrogen tanks. The
tanks must be reliable under all conditions
and at temperatures ranging between -60
and +60° C.
One of the major challenges is to find
materials that can resist the effect of
hydrogen which can make them brittle.
Special austenitic stainless steels meet
this requirement and have the high
strength required for this application.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Good mechanical properties � No coatings required
Grades: EN1.4548; AISI 630 ESR melted
EN1.4545; AMS 5659; ASTM 564
Strength and Toughness
AerospaceLanding Gear ComponentsAircraft landing gear components are subject to extreme stress
during both take-off and landing.
Re-melted martensitic stainless steels are preferred over
engineering steels for parts of the landing gear of commercial
aircrafts. The re-melted martensitic stainless provides good
mechanical properties, while avoiding the need of cadmium-
plating, which is now banned because of its toxicity.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Good mechanical properties
Grades: EN1.4542; AISI 630
Strength and Toughness
Oil and GasRotor shaftDirectional drilling, a major advance in oil technology, allows the
drilling of curved holes, usually to the horizontal into the oil-rich
formation.
A key element is the hollow helical shaped rotor shaft, which is
driven by high pressure water injected from the surface. The
resultant twisting forces drive the drill bit in a rotational motion.
MWD (Measurement while Drilling) electronic equipment allows
the positioning, and steering of the drill bit.
Rotor OD ranges from about 100 to 160 mm.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Biocompatibility � Good mechanical properties
Grades: EN1.4441 (ISO-5832-1) and
EN1.4472 (ISO-5832-9)
Strength and Toughness
MedicalImplantsStainless steel, together with titanium and cobaltbased alloys,
is widely used for surgical implants such as hip and knee joints,
fasteners and plates.
These implants may either be temporary or permanent.
The stainless is re-melted to ensure a high level of purity for
optimum biocompatibility and mechanical properties. Stainless
steel is also the preferred material for all surgical, dental and
medical tools and equipment.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Good mechanical properties � Aesthetics
Grades: EN1.4301; AISI 304
Strength and Toughness
RecreationalBicyle Wheel SpokesBicycle spokes are usually made of drawn stainless steel wire
for high strength (UTS > 1200MPa) while maintaining sufficient
ductility for the forming and threading of the spoke ends.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Good mechanical properties � Safety component � Aesthetics
Grades: EN1.4310; AISI 302
Strength and Toughness
RecreationalBicyle Brake CablesStainless brake cables are widely used in bicycles for their
mechanical resistance and are obviously critical safety
components.
They are also used for gear change systems.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Good mechanical properties � Low maintenance � Aesthetics
Grades: EN1.4542; AISI 630
EN1.4462; ASTM F51
Strength and Toughness
BuildingGlass Facade «Spiders»The glass panels on the façade are held in place by strength
“spiders” which carry the weight of the glass.
Although their primary function is mechanical, their appearance
does not detract from the overall elegance of the structure. They
are expected to last as long as the building itself without any risk
of damage or collapse.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Good mechanical properties � Durability
Grades: EN1.4057; AISI431, EN1.4301; AISI304
EN1.4401; AISI316
Strength and Toughness
ConstructionPost-Tensioning Tie RodsThe great Roman theatre, the symbol of Verona, dates back to the first half of the 1st
Century AD. It was once one of the most important open air opera theatres in the Roman
Empire.
Recent restoration work involved the construction of new covering for the central
orchestra pit, an underground room and the underground sewage tunnels.
The new covering slab is structurally supported by a system of roof struts and post-
tension tie rods. These minimise strains and deformation from loads placed on top. The
post tension system used, comprising stainless steel bars, guarantees structural safety,
quality and durability.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Aesthetics � Good mechanical properties
Grades: EN1.4401; AISI316
Strength and Toughness
ConstructionTensegrity® Glass BeamsA new type of glass panel beam has been developed at the University of Pisa, Italy.
The basic concept involves preventing and guiding glass fracture by breaking it into
triangular modular elements. The elements are connected to each other by applying
a pre-stress in the form of pre-tensioned stainless steel cables or bars. The glass is
predominantly subject to compression. The final collapse of the structure depends on the
ductility of the steel.
The structure relies on the principle of tensile integrity or Tensegrity as it is better
known. Tensegrity refers to the integrity of structures as being based in a synergy
between balanced tension and compression components.
All ancillary are made of stainless steel. This is for both aesthetic and durability reasons.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Good mechanical properties � Durability
Grades: EN1.4005; AISI410L
Strength and Toughness
ConstructionNedujinja Shrine BridgeIn the reconstruction of the bridge at the Nedujinja Shrine, grade
410 stainless steel rebar was chosen for its durability as a
reinforcement material in concrete structures.
A ferritic grade was selected over an austenitic grade because of
its low thermal expansion properties and low cost. About 1.2 tons
of stainless steel was used in the bridge.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Aesthetics � Resistant to harsh weather � Maintenance-free
Grades: EN1.4401; AISI316
Aesthetics
BuildingOutdoor Parking MeshThe carpark at Winnipeg International Airport is wrapped in
metal fabric, dramatically differentiating the exterior of the newly
constructed garage. This was the first airport project in Canada,
and one of the first in North America to target Leadership in
Energy and Environmental Design (LEED) Certification.
The Leadership in Energy and Environmental Design (LEED)
Green Building Rating System was developed by the United
States Green Building Council (USGBC) in 1998. It provides a
suite of standards for environmentally sustainable construction.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Aesthetics � Suitability for harsh weather conditions � Low maintenance
Grades: EN1.4401; AISI316
Aesthetics
BuildingDecorative MeshThe architect chose stainless steel for the cladding of this
building because of its aesthetic qualities, both by day and by
night.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Aesthetics � Good mechanical properties
Grades: EN1.4401; AISI316
Aesthetics
BuildingHandrail CableInitially used on yachts, these guard rail cables have found new
uses in buildings and other public spaces.
They enable elegant designs and still admit the maximum amount
of light.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Aesthetics � Smooth touch � Feeling of « sturdiness »
Grades: EN1.4301; AISI304
Aesthetics
BuildingDoor HandleAlong with their elegant look, these stainless steel door handles
provide a smooth touch and feeling of sturdiness.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Aesthetics � Smooth touch � Feeling of « sturdiness »
Grades: EN1.4404; AISI316L
EN1.4435; AISI316LMo
EN1.4439; AISI 904L
Aesthetics
Consumer goodsWatchesThe best-known luxury watch brands offer high quality stainless
steel models. Elegant design, superb finish, sturdy and lasting,
these watches deserve their well-earned reputation. Most watch
casings are manufactured from a high-quality stainless steel
piece by hot forging, precision machining and careful surface
finishing.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Durable � Good mechanical properties
Grades: EN1.4462 (ASTM F51)
EN1.4362
Environment
BuildingThermal Insulation InsertsThe connector is a structural component used to join external concrete
balconies to internal concrete floor slabs. Stainless steel reinforcement bars
provide the load transfer and have a long service life. Rigid chlorofluorocarbon-
free polystyrene insulation offers improved thermal protection. The connectors
are easy to handle and to install.
Stainless steel provides the required strength, corrosion resistance and
maintenance-free life in all weather conditions.
This system improves the thermal insulation of buildings by avoiding cold
bridging, thereby reducing heat losses and improving comfort inside.Balcony connectors in place before concrete is poured
Connectors awaiting installation of the balcony
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Oxidation resistance (hot gases)
Grades: EN1.4113; AISI434
Environment
AutomotiveSteel WoolSilencer wool is used in automotive exhausts to reduce noise emissions from
the vehicle.
Stainless competes with glass and direct-cast metallic fibres in this application.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Fire resistance
Grades: EN1.4404; AISI316L
Fire Resistance
ConstructionAnchors of the tunnel claddingThe Mont Blanc tunnel between Italy and France was the scene of a terrible fire in March 1999 which
claimed many lives. The tunnel re-opened following three years of extensive work to repair the
damage caused by the blaze.
Safety precautions in the tunnel are now extremely tight. Particular attention is paid to the fire
resistance in all components in the tunnel.
The Italian National Roads Authority has published a circular which contains directives for the
construction of tunnels. Stainless steel, thanks to its characteritic stability and resistance to high
temperatures, is cited as the material of choice for the fabrication tunnel components such as smoke
extraction fans and lighting systems.
The system used to anchor the fibre cement cladding panels that line the Mont Blanc tunnel is now
composed of 16 mm stainless anchors. The anchors have been tested to ensure they maintain their
support function for at least two hours at 1,000° C.
Non-Corrosion Properties of Stainless Steels
Why Stainless Steel? � Fire resistance � Good mechanical properties
Grades: EN1.4301; AISI 304
Fire Resistance
ConstructionAnchoring HeadsAnchoring heads of cables in the Pirelli building.
In April 2002, a light aircraft hit the Pirelli skyscraper in Milan, Italy. At least five people were killed
in the accident and more than 30 injured.
The top floors of the 30-storey building caught fire. In particular, serious damage was caused to the
26th and 27th floors. The planking of the 26th floor took on a concave shape, bending more than
25 cm, while the floor of the upper story took a slightly convex shape.
Restoration of the structure involved inserting a group of post-stretched cables. The anchoring of
the heads of the active-reinforcement cables (or noses) against the core of the beam in reinforced
concrete was done by means of 28 mm threaded stainless steel bars with a yield stress of >800 Mpa.
Non-Corrosion Properties of Stainless SteelsISSF Members producing stainless steel long products
Aichi Steel Corporation Japanhttp://www.aichi-steel.co.jp
Baoshan Iron and Steel Co. Chinahttp://www.shno1steel.com
Böllinghaus Germanyhttp://www.boellinghaus.de
Cogne Acciai Speciali Italyhttp://www.cogne.com
Daido Steel Co. Ltd. Japanhttp://www.daido.co.jp
Deutsche Edelstahlwerke GmbH Germanyhttp://www.dew-stahl.com
Nippon Steel and Sumikin Stainless Steel Corporation Japanhttp://www.ns-sc.co.jp
North American Stainless (NAS) USAhttp://www.northamericanstainless.com
Outokumpu Oyj Finlandhttp://www.outokumpu.com
Roldan S.A. Spainhttp://www.acerinox.com
SeaH Changwon Integrated Special Steel Corp. Koreahttp://www.seahss.co.kr
Ugitech S.A. Francehttp://www.ugitech.com
Non-Corrosion Properties of Stainless SteelsPhoto Credits
Iconos S.A., France
Alstom Switzerland S.A., Switzerland
Kanthal A.B., Sweden
Velan SAS, France
Deutsche Edelstahlwerke GmbH, Germany
Adam Opel GmbH, Germany
Ugitech S.A., France
Centro Inox, Italy
JSSA, Japan
Cambridge Architectural Inc., USA
Ancon Building Products Inc., UK
Nuova Temas, Italy
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